1. Field of Invention
The present invention relates to a BLUETOOTH® mobile communication system, and more particularly to a master-slave BLUETOOTH® mobile communication system and a network domain login method, by which two network domains can be logged into.
2. Related Art
In an early day, a band-held device can only provide for logging in to a single network domain, wherein a subscriber selects their appropriate network domain from different telecommunication vendors, according to his or her requirement. However, if subscribers have to make lots of calls or need a long time interaction and communication with a remote device of other network domain, cost will be quite expensive. In addition, more and more subscribers own two or more network domain accounts, and for each account, the user requires to purchase a cellular phone to put an identification module built-in with the network domain account therein; hence, the subscriber will need to carry plural cellular phones for a possible need. Moreover, the electromagnetic waves produced by the cellular phones are very strong and can affect people's health significantly, such that cellular phone vendors brought up a dual mode cellular phone, allowing a subscriber to use two network domain accounts in one cellular phone, thereby reducing the amount of electromagnetic waves.
Yet, the prior art is still provided with unavoidable shortcomings as described below.
First of all, the dual mode cellular phone refers to a cellular phone which is equipped with two different communication modes to log in to two identical or different network domains. However, the communication modes configured in the dual mode cellular phone are fixed and unchangeable. Therefore, for a subscriber who owns plural network domain accounts, he or she cannot change freely the network domain account for use according to his/her preference; it is still inconvenient in application.
Secondly, the dual mode cellular phone is built in with two different communication modes to log in to different network domains. When each communication mode activates a telecommunication connection, a quite amount of electromagnetic waves will be emanated. Thus, the amount of electromagnetic waves produced by the dual-module cellular phone will be about a total sum of the amount of electromagnetic waves from all the communication modes. Comparing to a single mode cellular phone, the dual mode cellular phone affects and harms people's health more severely.